Surface-functionalization of isotactic polypropylene via dip-coating with a methacrylate-based terpolymer containing perfluoroalkyl groups and poly(ethylene glycol)

Isotactic polypropylene (PP) is one of the most popular plastics. However, the remarkably low surface energy of PP prevents the surface functionalization of PP. We studied the surface functionalization of PP by dip-coating with a maleic anhydride-grafted chlorinated polypropylene (MPO)/methacrylate-based terpolymer mixture. A methacrylate-based terpolymer (PMFP) was synthesized, which contained perfluoroalkyl (Rf)-conjugated monomers and poly(ethylene glycol)-conjugated monomers. Tape-peeling tests revealed that MPO successfully immobilized PMFP on a PP surface, although PMFP was less adhesive to PP. X-ray photoelectron spectroscopy (XPS), contact angle, and protein adsorption measurements revealed that the Rf groups and PEG chains in PMFP were segregated to the outermost surface of the dip-coated layer. The surface segregation of these moieties produced a low-fouling surface on the PP substrate. In addition, we synthesized a terpolymer that contained Rf groups and PEG chains with carboxy groups at their termini (PMFB) and used it to dip-coat a PP substrate. The surface segregation of side chains in PMFB induced the presentation of carboxy groups at the outermost surface, which were used as reactive sites for enzyme immobilization